Fig. 3

Panel A shows the Cabrera presentation of leads. The leads are presented in contiguous order. Compared to the standard format, aVR is replaced by –aVR. The relation between the limb leads according to the frontal axis is evident in Panel B. The Cabrera sequence is demarcated by the dashed lines above lead aVL and to the left of lead III. Lead aVR, which is included in standard display, is completely different from the other leads, with its positive pole in the upper right quadrant of the thorax. In the Cabrera display, the inverted version −aVR instead bridges the gap between lead I and II, resulting in a smooth waveform progression. This ECG, from a patient with RCA occlusion, shows significant ST elevation in only one lead, lead III, but reciprocal ST depression in aVL. Since −aVL is opposite to aVL and next to III, significant ST elevation can be considered to be present in two contiguous leads, III and − aVL